Leave a comment on the Post’s Web site under this article, and chances are good that its subject, artist Jeff Gates, will reply. Gates recently installed some buzz-worthy art on the Red Line platform at the Gallery Place-Chinatown Metro station, and if you have something to say about it, he wants to hear it.

“I’ll debate anyone about these posters,” he said. “And I’ll say yes, I’m a liberal, but that isn’t really what they’re about.”

What the poster — and another soon to appear at the Farragut West station — are about is the way we debate each other. Under the name the Chamomile Tea Party, Gates is on a crusade to bring civility back to political discourse through a form of art not known for its subtlety or objectivity: propaganda posters. Inspired by the way that propaganda united Americans during World War II, he has used that visual language to explore why people are so politically divided in the walk-up to this year’s election. Instead of war bonds and victory gardens, Gates is trying to promote honesty, moderation and civility.

“I think propaganda is very much a part of our lives now, but it’s couched in very different ways, very benign ways. . . . We really have to be even more aware of what messages mean,” he said. In World War II propaganda, he said, “the lines were so clear between right and wrong, between the Axis and the Allies. . . . The parameters of this discussion are much less black and white.”

Gates got the idea for the posters on July 3, 2010, while listening to NPR as he walked home from the Metro.

“They had a story about the nomination of Elena Kagan, and they said that all of the Republicans were going to vote against it based on party lines. All of a sudden, I got really upset,” said Gates. “Yes, she was liberal, but she wasn’t a raving liberal. And to count her out simply because of party affiliation, it became very clear to me that party politics was countering governance.”

Gates has been distributing his posters online for free ever since, and they’ve popped up in surprising places. He said he was particularly excited to see them at the 2010 Rally to Restore Sanity and/or Fear, presented on the National Mall by comedians Jon Stewart and Steven Colbert. But with the election drawing near, Gates wanted to get his message to a broader audience. It may have already reached you if your Red Line commute takes you to Gallery Place-Chinatown, where Gates has purchased advertising space to install one of his Chamomile Tea Party posters.

According to Cathy Asato of Metro’s media relations department, this is the first time an artist has purchased advertising space to showcase art.

Gates says he paid about $3,400 for the ad spaces and versions of the posters suitable for Metro’s back-lit display. He received a discount because he submitted the posters through his nonprofit, Art FBI (Artists for a Better Image), which works to combat stereotypes of artists. At his day job, Gates’s title is lead producer, new media initiatives at the Smithsonian American Art Museum, which makes him a federal employee. But because his political art doesn’t explicitly promote a candidate, it’s permissible under the Hatch Act, which governs the political activities of government workers.

Both liberals and conservatives could rally behind the posters that Gates selected for his Metro ads.

The posters “could be about either party, or could be about both parties. It’s about human experience. . . . It’s talking about our ability to work together,” he said.

The Gallery Place-Chinatown poster, with an image of a man drowning, reads: “I lost my job and my home and my health care and my retirement and my self-esteem while you played party politics.”

Another, which is scheduled to go up in October at the Farragut West station on the Blue and Orange Lines, features a machine with two gears — liberals and conservatives — halted by a bloody bayonet labeled “Disunity,” with the warning, “We’re losing our competitive edge.”

But look at the Chamomile Tea Party’s body of work, and it’s obvious where Gates’s loyalties lie: Though he addresses Democratic weakness in some posters, such as “Mothers of Democrats: Give your children more milk to build stronger backbones,” more complaints are addressed at Republicans.

Andrea Pollan, owner of the Curator’s Office gallery, was drawn to his work because she saw it as a continuation of Shepard Fairey’s propaganda-inspired Obama posters during the 2008 election.

“Whenever I focus on works of a political nature, I prefer for them to be super-open-ended, not super-didactic,” said Pollan, who will play host to an exhibit of Chamomile Tea Party posters Oct. 27 through Nov. 7. “A lot of us are so tired. He nailed that in the various posters.”

Gates isn’t sure how the public will react to his posters, but he intends to find out: He plans to linger near his ad and eavesdrop on anyone who notices it. If they complain, that’s all right — he’d like to have a rational and respectful conversation with them.

The worst-case scenario is if people walk by without noticing the poster. Calling for civility during an election year is a Sysiphean act, after all — it’s shouting into a crowded room.

“I sat in on a discussion with some political wonks and they said, ‘This is the way it is, get used to it,’ ” Gates said. “I’m sorry, but I will never like it, and I will never get used to it.”